JPS63173858A - Rotary swash plate type compressor having main shaft supported in cantilever form - Google Patents

Abstract

PURPOSE:To bring a main shaft and a rotary swash plate into uniform surface contact with their respective bearing by establishing the inclining angle of the main shaft to a rotary swash plate, that of a thrust race surface of the rotary swash plate, and that of the main shaft to a bearing to their specified angular relations respectively. CONSTITUTION:When the thrust bearing surface of a rotor 14 serving as a rotary swash plate is denoted by ST, and an axis perpendicular to the thrust bearing surface ST by OR, a main shaft 16 is attached with its center axis OS inclined at the angle of theta1 from the above-mentioned axis OR toward the top dead center of the rotor 14. When the axial length of a radial bearing 15 is denoted by l, and a clearance between the bearing 15 and the main shaft 16 by c, the angle of theta1 is selected so as to satisfy the mormula of theta1=tan<-1>(c/l). The thrust race surface of the rotor 14 is formed in a taper surface inclining on the side of the top dead center to form a falling gradient having a fixed angle theta2 smaller than angle theta1 in radially outward direction. In addition to that, the center axis OS of the main shaft 16 is inclined at a fixed angle 8 from the center axis OB of a bearing 15 toward the top dead center.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotating swash plate type compressor, and particularly to an improvement of this type of compressor having a structure in which the main shaft is supported in a cantilevered manner.

[Prior art]

Rotating swash plate compressors with a structure in which the main shaft is cantilevered are known from U.S. Patent No. 3,552,886, U.S. Pat. be.

A typical structure of this type of compressor will be explained with reference to FIG.

In FIG. 6, a cylindrical cousing 10 is located between a cylinder block 11 fitted and fixed at one end and a front housing 12 fixed at the other end.

A crank chamber 13 is formed which also serves as a storage chamber for lubricating oil. A wedge-shaped rotor 14 with a rotating swash plate arranged in the crank chamber 13 is fixed to a main shaft 16 that is rotatably inserted through the center of the front housing 12 via a radial needle bearing 15. It faces the front housing 12 via a thrust needle bearing 17.

Also inside the crank chamber 13. Inclined surface 14a of rotor 14
A ring-shaped rocking plate 19 is arranged opposite to each other via a thrust needle bearing 18.

This swing plate 19 is swingably received at the tip of a swing center shaft body 20 via a steel ball 21 that is rotatable once. The swing center shaft body 20 is fitted into the center hole 22 of the cylinder block 11, and is movable in the axial direction, but is prevented from rotating. It is energized towards 19. What is the biasing force of the spring 23 at this time?

It can be adjusted by turning the screw body 24 screwed into the central hole 22.

The oscillating center shaft 20 also has a bevel gear 20b at its tip, and when this bevel gear 20b meshes with a bevel gear 25 fixed to the oscillating plate 19, the oscillating plate 19 rotates. is being prevented.

Furthermore, a plurality of cylinders 26 are formed in the cylinder block 11, and a piston 27 is slidably inserted into each of the cylinders 26. These gistons 27 are connected to the vicinity of the periphery of the swing plate 19 by rods 28. The connection between the rod 28 and the swing plate 19 and the connection between the rod 28 and the piston 27 are as follows.
Both are done using a ball and socket joint.

Further, a cylinder head 30 is superimposed on one end of the cylinder block 11 via a gasket (not shown) and a valve plate assembly 29, and? It is fixed there by a seat 31. The cylinder head 30 has a suction chamber 32 near the outer periphery.

It has a discharge chamber 33 in the center. Valve plate assembly 29
is a valve plate having a suction port 34 that connects each cylinder 26 to a suction chamber 32 and a discharge port 35 that connects each cylinder 26 to a discharge chamber 33;

a flexible suction valve provided on the cylinder 26 side of the suction port 34;
A flexible discharge valve provided on the discharge chamber 33 side of the discharge port 35 is fixed together with a fixing bolt 36.

Note that 37 is a valve holder for preventing excessive deflection of the discharge valve, and this is also integrally fixed to the valve plate assembly 29 with a fixing bolt 36.

In the above-described structure, when the main shaft 16 is rotated by an appropriate rotation drive means, the rotor 14 rotates within the crank chamber 13, and the swing plate 19 rotates the steel ball 21 according to the slope of the rotor 14. Since it oscillates without rotating around the center, the plurality of pistons 27 move around the cylinder 26 based on this.
As a result, the suction chamber 3
The fluid of No. 2 is sucked into the cylinder 26 through the suction port 34, and is discharged into the discharge chamber 33 through the discharge port 35.

Actually, the suction port 38 provided in the cylinder head 30
A cooling port is provided between the cooling port and the discharge port (not shown).

Note that the biasing force of the spring 23 is applied to the thrust bearing 17° and the roller 14. Thrust bearing 18. Rocking plate 19. Bevel gear25. Steel ball 21. It is adjusted by the screw body 12 to ensure an appropriate axial clearance between each of the swinging center shafts 20, and also prevents axial movement of each part due to dimensional changes due to temperature changes or machining dimensional errors of each part. Acts as an absorber.

[Problems to be solved by the invention]

For example, the rotary swash plate type compressor having the above-mentioned configuration has nine examples.

It is used as a refrigerant compressor for car coolers and has a sufficient lifespan under normal use.

When used under severe conditions, the rolling or sliding parts may seize, making it impossible to guarantee a sufficiently long life.

When investigating the cause of this seizure, we found that peeling had occurred on the contact surface of the radial needle bearing of the main shaft 16 and the contact surface of the thrust needle bearing of the rotor 14, and the pieces were scattered on the rolling and sliding parts. It was found that this caused damage to the clutch and eventually caused seizure of the clutch sliding and rolling parts.

FIG. 7 is a developed view of the bearing contact surface of the main shaft 16.

In the figure, separation occurs in area A, and area B shows contact with the bearing. It had a shiny surface. That is,
The main shaft 16 does not contact the bearings uniformly.

It turned out that there was a bias.

This type of redundancy is thought to be due to the following reasons.

The external force acting on the rotor 14 is the total gas pressure F1 based on compression by the piston 27 and the urging force F1 by the spring 23.
It is 2. As shown in FIG. 8, the total gas pressure F1 acts at a point A near the connection point with the piston rod 28 of the piston at the top dead center. That is.

This is near the outer circumference of the rotor 14 in the axial direction.

This point A side of the rotor will be referred to as the top dead center side of the rotor. The biasing force F2 is applied to the center of the rotor 14.

However, since the total gas pressure F1 and the q biasing force F2 both act on the inclined surface of the rotor, the component force F3. F4 respectively.

A reaction force F5 is generated from the thrust bearing 17 against the axial pushing force (F1+F2), and the axial force is balanced, but there is no force that balances the radial resultant force (F3+F4), so the rotor 14 is pushed toward the top dead center side, and a moment of counterclockwise rotation is generated around the contact point B with the thrust bearing 17 (see Fig. 8).
? receive. As a result.

The rotor 14 floats up from the thrust bearing 17 at the bottom dead center side opposite to the top dead center side with respect to the center. This movement of the rotor toward the top dead center side and the floating of the bottom dead center side result in the relatively small rigidity of the rotor and the main shaft, especially at the connection point, so the main shaft 16 is tilted as shown in the figure, and the radial bearing 6 points and 0
You will be given points. The inclination of the principal axis at this time is θ
Adashi.

This is determined by the axial length of the radial bearing and the radial clearance. In this state, the radial bearing 15
1 reaction force from F6. F acts on the principal axis, F3+
Balanced at F4=F6-F7, each dimension t1~1,
If r and r are determined as shown in FIG. 8, Mornont is also maintained in the following equilibrium state.

F3t1+F4t2+F67-5 Fl (r2
r+) F2r2-F7t4=0 In this way, the main shaft 16 rotates with an inclination of θ while rotating against the radial bearing.

It is thought that this causes the above-mentioned peeling. Due to this inclination θ, a reaction force F6 acts from the radial bearing on the main shaft. F changes depending on the total gas pressure F1 and becomes large during high-load operation, so peeling is likely to occur under the above-mentioned severe conditions.

Of course, this θ depends on the clearance between the radial bearing and the main shaft, but it is approximately 0° to 0.04 with a normal clearance.
It is about °.

As mentioned above, the rotor 14 is affected by the moment.

By lifting up from the thrust bearing 17 on the bottom dead center side, the thrust surface also becomes inclined with respect to the thrust bearing surface by at least θ. As a result, the radially outer side of the thrust race surface on the top dead center side of the rotor hits the crown portion of the thrust needle bearing. This contact force is also large when the total gas force 1F is large, so peeling is likely to occur due to high load operation of the compressor.

Based on this knowledge, the present invention eliminates uneven contact between the main shaft and the radial bearing that supports it, as well as rotation between the rotor and the thrust bearing, even when the compressor is operated under severe conditions. It is an object of the present invention to provide a compressor in which a main shaft and a rotor are supported by their respective bearings with uniform surface contact, thereby achieving a sufficient lifespan even when used under severe conditions.

[Means for solving problems]

The present invention rotatably supports a main shaft via a radial twenty dollar bearing in a front housing, a wedge-shaped rotating swash plate is attached to the end of the main shaft inside the crank chamber, and the rotating swash plate is attached to the inner surface of the front housing using a thrust needle. Rotation in which the main shaft is cantilever-supported so that the piston is thrust-supported through a bearing and reciprocated through a rocking plate that is pressed with an axial pressing force to allow relative rotation on the inclined surface of the rotating swash plate. In the swash plate type indentation machine, the main shaft is attached to the rotating swash plate at a small angle θ toward the top dead center of the piston with respect to its thrust support surface. Set the clearance to C.

When θ=tan-' (c/z), θ1>θ) is installed at an angle of θ1>θ), and the race surface of the rotating swash plate that comes into contact with the thrust needle bearing is at least above the piston. The part corresponding to the dead center side is formed as a chi/mother surface that is inclined outwardly away from the thrust support surface by a small angle θ2 (θ1>θ2), and the rotor and main shaft are Due to the axial pressing force, the central axis of the main shaft is inclined toward the top dead center by a slight angle θ (θ, -θ2〉0) with respect to the central axis of the radial needle bearing, and the chie surface is tilted toward the thrust needle. It is characterized in that it is attached so as to make contact with the bearing.

[Effect]

According to the present invention, when the compressor operates and gas pressure is applied to the rotating swash plate, the component force of the gas pressure on the inclined surface of the rotating swash plate causes the main shaft to move to the top dead center side along with the rotating swash plate. Pushed. Therefore, the main shaft is displaced relative to the rotating swash plate, and this displacement produces a displacement angle corresponding to the acting moment based on the joint rigidity between the two-turn swash plate and the main shaft, and as a result, the outer surface of the main shaft is at the top of the radial needle bearing. It will uniformly contact the surface on the point side.

Further, on the top dead center side of the rotating swash plate, the Q-9 surface of the inclined thrust race is also kept in uniform contact with the thrust needle bearing. As a result, even under severe conditions, the main shaft and rotating swash plate do not come into contact with the radial needle bearing and the thrust needle bearing, thereby preventing the conventional peeling phenomenon.

〔Example〕

The invention will now be described in detail with reference to one drawing.

FIG. 1 shows a rotor 14 used in carrying out the present invention.
FIG. 4 is a sectional view showing an assembly of the main shaft 16 and the main shaft 16 before being assembled into the front housing.

Referring to the figure, the main shaft 16 is attached at an angle with respect to the rotor 14. That is, the surface of the rotor 14 that is thrust supported (this is called the thrust support surface) is ST
If the axis perpendicular to this thrust support surface STK is OR (hereinafter referred to as the center axis of the rotor), then the main shaft 16 was installed so that its center axis 0 was parallel to OR in the past. , In this example, there are two shown in the figure. It is installed in a state where it is tilted by θ from 11OR toward the top dead center side of the rotor (that is, toward the thicker side of the rotor).

This 0. is a lanoal bearing (Fig. 2 and Fig. 9 15)
θ where the axial length is l and the clearance with the main axis is C
, >tan-' (c/l). θ, ba.

The angle is approximately 0.5°.

Further, the rotor 14 is provided with a ring plate-shaped thrust race that comes into contact with the thrust bearing 17 explained with reference to FIG. chosen small. More specifically, when the aforementioned tan-' (c/l) is θ, it is selected so that θ, −02≧θ. Preferably, θ, -02>θ is selected.

Note that the thrust race surface is only on the top dead center side (cheating surface 14a).
It is also possible to close the entire surface without cutting.

FIG. 2 is a sectional view showing a state in which the rotor and main shaft assembly shown in FIG. 1 is assembled into a compressor.

Rotor 14. Outside the main shaft 16 is a front knob A unong 1.
2. Lanoal bearing 15. Only the thrust bearing 17 is shown, and the other parts and related configurations are the same as in FIG.
Illustrations are omitted.

Referring to FIG. 2, the main shaft 16 is inserted into the radial bearing 15 of the front housing 12, and the biasing force of the spring 23, the main shaft 16 and the rotor 14 are adjusted by adjusting the annoyast screw 24 shown in FIG. By adjusting the axial biasing force corresponding to the displacement color due to the coupling rigidity of the
the thrust bearing 17. The axial biasing force for the displacement color due to the spring 23 and the joint rigidity of the main shaft 16 and rotor 14 at this time is defined as F2.

That is, this biasing force F2 overcomes the rigidity of the joint between the rotor 14 and the main shaft 16, and pushes the bottom dead center side of the rotor 14 toward the front housing 12. As a result, the rotor central axis OR moves by an angle Φ to the position OR' compared to before adding F2. At this time, the angle between the central axis OB and OR' of the radial bearing 15 is θ2, and the angle between the central axis O of the main shaft 16 and the central axis of the radial bearing is θ=tan-' as described above.
c/l. That is.

Due to the biasing force F2, the main shaft 16 is moved to the first position relative to the rotor 1.
It is maintained in a state where it is deviated by Φ=θ,′″ (θ+02) from the mounting angle shown in the figure.As a result, if the rigidity coefficient of the joint between the RONITA 14 and the main shaft 16 is k.

In FIG. 2, where M=Φ, a clockwise moment acts on the main shaft 16. In the state shown in Figure 2, the balance between force and moment is expressed by the following equation.

F4+F6=F7 F2=F5 F5・R+F6t2-F4l, -F7(t2+tρ=
OM, = kΦ = F7 (Z2 10ts)
F 6t2 Here, l, , t2+ t31 R
represents the dimensions of each part as shown in Figure 2 + F2 +
F4 r F5 + F6 + F7 are the forces that act as shown in FIG. That is.

F2: Axial biasing force of the displacement color based on the joint rigidity of the spring, shaft, and rotor F4: Component force on the rotor inclined surface of F2 (assuming the inclination angle of the rotor inclined surface is α, F4 = F2, theory α) F5: Resistance from the thrust bearing 17 F6: Resistance from the radial bearing F7: Resistance from the radial bearing In the setting state shown in Fig. 2.

Since the biasing force F2 presses the rotor 14 with a force large enough to generate the moment M as described above, the rotor 14. Thrust bearing (Fig. 6, 18).

Swing plate (Fig. 6, 19), bevel gear (Fig. 6, 25).

Steel ball (Fig. 6, 21) and swing center shaft (Fig. 6, 2)
There is no axial clearance between 0).

In this state, when the compressor is operating, when gas pressure F is applied to point A on the top dead center side of the rotor 14, as shown in FIG. moves to the top dead center side. At this time, the main shaft 16 receives the moment M8 and is brought into contact with the outer end B of the radial bearing 15, as described above.

The rotor side of the main shaft 16 moves toward the upper fulcrum using point B as a fulcrum, and comes to uniformly contact the inner surface of the bearing 15 on the top dead center side, as shown in FIG. That is, the main shaft 16 is further displaced from the state shown in FIG. 2 by θ, that is, from the inclination angle θ shown in FIG. It becomes parallel to the axis o8.

In addition, as mentioned above, the rotor thrust bearing - oscillating plate - bevel gear - steel ball - oscillating center shaft (14-18-19 in Fig. 6)
There is no axial clearance between -25-21-20),
The lifting of the bottom dead center side of the rotor 14 is prevented. That is, the axial biasing force applied to the rotor 14 becomes a force F2' which is increased from F2 by the force that prevents the rotor from lifting up. Due to this.

The component force F4' of F2' also becomes a dog by F4 in FIG.

In this way, while the compressor is operating, it is balanced as shown in Figure 4, and the thrust race on the top dead center side of the rotor is balanced.
As shown in FIG. 5, the groove surface 14a is kept in uniform contact with the thrust bearing 17 as in FIG. 2.

This balanced state is expressed by the equations of force balance and moment balance as follows.

F3+F4'=F6 F, 10 F21=F5 F5・R-F4'・l, -F, R'-F6 (t2+t4
) = 0M8' = k (to φ10) = F6 (t2 + t4)
Here, r l, r t2 r t5 + RHR' is
With the dimensions shown in Figure 4 l F2Z F4'+ 7 r
F3 is the force as described above, and F5 is the force of thrust bearing 1.
Drag from 7.

F6 is a drag force 9M' from the lanoal bearing 15, which is a clockwise moment applied to the main shaft due to the main shaft being displaced by (Φ+θ) from the mounting inclination angle θ to the rotor 14.

In this way, during operation of the compressor, the main shaft 16 contacts the lanoal bearing 15, and the roller trace surface contacts the thrust bearing 17 at its chi 1 surface 14a uniformly without bias. Due to this.

Peeling is prevented.

〔Effect of the invention〕

As described above, according to one aspect of the present invention, the main shaft is rotatably supported on the front shaft via a radial needle bearing, a wedge-shaped rotating swash plate is attached to the end of the main shaft in the crank chamber, and the rotating swash plate is attached to the end of the main shaft in the crank chamber. The plate is thrust-supported on the inner surface of the front housing via a thrust needle bearing, and the piston is reciprocated via a rocking plate pressed with axial pressure on the inclined surface of the rotating swash plate so as to be relatively rotatable. In a rotating swash plate compressor with a main shaft supported in a cantilever manner.

The main shaft is attached to the rotating swash plate at a small angle θ toward the top dead center of the piston with respect to its thrust support surface (however, the axial length of the lasoal bearing is l, and the clearance with the main shaft is C).
And when θ= tan-' (c/l), θ1
>θ), and the race surface of the rotating swash plate that contacts the thrust needle bearing is tilted outward at least in a portion corresponding to the top dead center of the piston toward the thrust support surface. Qi 9 tilted by a small angle θ2 (Ol>θ2) away from
Moreover, the swash plate and the main shaft are arranged such that the central axis of the main shaft is slightly angled θ toward the top dead center side with respect to the central axis of the radial needle bearing due to the axial pressing force.
It is tilted by (0, -θ2〉θ) and the above chi
Since the structure is such that the P surface is in contact with the thrust needle bearing, the rotating swash plate receives a radial force directed toward the top dead center due to the gas pressure applied to the rotating swash plate during compressor operation. . Therefore, a moment based on this force acts on the rotor, resulting in a displacement angle based on the joint rigidity of the shaft and rotor. Therefore, the main shaft uniformly contacts the top dead center side of the radial needle bearing surface without bias. Further, the tapered surface of the thrust race of the rotating swash plate also uniformly presses into contact with the thrust needle bearing. The rotary swash plate compressor of the present invention can be used even under severe conditions.
This has the advantage that peeling does not occur on the thrust race surfaces of the main shaft or rotor, resulting in a longer life.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an assembly of a main shaft and rotor according to the present invention, and FIG. 2 is a cross-sectional view of essential parts according to an embodiment of the present invention.
FIG. 3 is an enlarged view of the T section in FIG. 2. Fig. 4 is a sectional view of the main parts similar to Fig. 2 showing the compressor in operating state F, Fig. 5 is an enlarged view of the T section in Fig. 4, and Fig. 6 is a cantilevered view of the main shaft. A sectional view of a conventional example of a supported rotary swash plate compressor, Figure 7 is a developed view of the outer surface of the main shaft supported by the bearing after long-term use in the conventional example, and Figure 8 shows the force applied to the rotor in the conventional example and its FIG. 2 is an explanatory diagram showing the state of the rotor and the main shaft according to the invention. 12...Front housing, 13...Crank chamber. 14... Rotor (rotating swash plate), 15... Radial needle bearing, 16... Main shaft, 17... Thrust needle bearing, 19... Rocking plate, 27... Piston, 14
a...Chi/6th surface of thrust race, ST...Thrust support surface.ゝ〈Nee-nee' Fig. 1, 5, Fig. 7, 1 - Circumferential direction 111

Claims (1)

[Claims] 1. A main shaft is rotatably supported in the front housing via a radial needle bearing, a wedge-shaped rotating swash plate is attached to the end of the main shaft inside the crank chamber, and the rotating swash plate is attached to the inner surface of the front housing via a thrust needle bearing. A rotary swash plate type compressor in which a main shaft is cantilevered and the main shaft is thrust-supported and the piston is reciprocated via a rocking plate which is pressed with an axial pressing force so as to be relatively rotatable on the inclined surface of the rotary swash plate. , the main shaft is attached to the rotating swash plate at a small angle θ_1 toward the top dead center of the piston with respect to its thrust support surface (where the axial length of the radial bearing is l, the clearance with the main shaft is C, θ=tan＾−＾1(C/
l), the rotating swash plate is installed at an angle of θ_1>θ), and the race surface of the rotating swash plate that comes into contact with the thrust needle bearing is at least the part corresponding to the top dead center side of the piston. A small angle θ_2 (θ_
The rotor and the main shaft are formed as tapered surfaces inclined by an angle of 1>θ_2), and the center axis of the main shaft is moved upward to the top dead center side with respect to the center axis of the radial needle bearing due to the axial pressing force. A small angle θ (θ_
1-θ_2≧θ) and is mounted so that the tapered surface contacts a thrust needle bearing.